H.323 trunk to Quescom GSM box issues

[James Hawkins]

Hi,

I have a customer running CUCM 7.1(2) who has two Cisco voice gateways each with one PRI and a Quescom GSM gateway with four SIMM cards allowing four calls. The Cisco voice gateways are configured as H.323 gateways and the Quescom GSM gateway is accessed as a non-gatekeeper inter-cluster trunk as recommended in the Quescom config guide which is attached to this post.

I have set up  the dial plan such that calls to mobiles hit a route list with two route groups. The first route group contains the Quescom GSM gateway and the second route list contains the two Cisco PRI gateways.

My issue is that when all four channels on the Quescom gateway are in use and I attempt to place a fifth call I get an Annunciator message stating "Your call cannot be completed at this time". What I would like to happen is for the fifth and subsequent calls to be routed via the Cisco PRI gateways.

I have seen from the logs available on the Quescom unit that the fifth call to it is rejected with a Q.931 cause code of 22 - No circuit/channel available.

I have done some research and changed the values of the CUCM service parameters Stop Routing on Unallocated Number Flag and Stop Routing on User Busy Flag to false but this does not resolve the issue.

Can anyone suggest how this issue may be resolved.

thanks

James

[James Hawkins]

Update

I have patched the software version running on the Quesom unit to the latest available but still have the same problem. I cannot put this into the production network as it effectively limits the number of concurrent calls to mobiles to four.

Anyone have any ideas on how to proceed with this issue?

[James Hawkins]

I have managed to get some traces off CUCM and have found it was a dial plan problem

I had configured the route pattern to discard digits predot to get rid of the PSTN access code before sending the call to the Quescom box. When all the channels on that unit were in use the call went to the PRI gateway but that did not have a matching dial peer as it is configured to accept  the PSTN access code  and so it generated a 0x8081 - Unallocated/unassigned number error.

I have configured the digit discard in my route list route group config and calls are being routed ok now.

The next problem is that calls into the Quescom box are not accepting DTMF tones.

[Service Desk]

Hi James,

were you able to solve the DTMF issue? We are getting a similar problem here after an upgrade to 5.11 version.

Thank you.

Best regards,

Norberto

[mamaral]

Hi!!!

Did anyone been able to solve this. I have the same problem with cucm 7.1

[James Hawkins]

Hi Guys,

I never managed to get the DTMF issue resolved. Please update the thread if you have more success.

[Francisco Sequeira]

Hi everyone,

I had the DTMF issue with a Quescom gateway and solved it going to :

QPortal >License and Profile>VOIP Profile

and ticking the "DTMF out of band Support" and the "RFC2833 Support" in the Profile applied to my Object > Foreign Gatekeeper (My Cisco CallManager)